Edit testcases directly from runner_ui.

[basit2]

is it possible to configure so that testcases can be directly edited from runner_ui standard input window?

[xeluxee]

is it possible to configure so that testcases can be directly edited from runner_ui standard input window?

Currently it's not possible, but it looks like a good idea. PRs are welcome.

[mengh04]

like this? #76